3 issues with my Galaxy S IISupport

2) When I try to change some things in Settings>Call, it says 'Network or SIM card error' and some of the options are greyed out so I can't change them.

3)When I try to connect to a Mobile network in Settings>More...>Mobile networks>Network Operators, it says 'Unable to connect. Try later', it happens with all of the available networks which are Virgin,O2 -UK, 3 UK, virgin (Yes, it was repeated) and Vodafone UK.

By the way, I've put in a new SIM card and it has solved problems 2 and 3, I haven't tried calling anyone yet, so I don't know if problem 1 is solved but nonetheless, my luck seems to be improving and I may have a solution to the issues I've been having.

If the problems occur with the new SIM card as well, I still have one last spare card to use.